The effect of hot multistage drawing on molecular structure and optical properties of polyethylene terephthalate fibers

In this work, mechanical and structural parameters related to the optical properties of polyethylene terephthalate (PET) fibers drawn at hot multistage have been investigated. The changes in optical parameters upon changing draw ratio are used to obtain the mechanical orientation factors and , various orientation functions f2(θ), f4(θ) and f6(θ), and amorphous and crystalline orientation functions (f a and f c). Also, the numbers of random links between the network junction points (N1), the average optical orientation (Fav), and the distribution function of segment ...